The Protective Effect of Lycopene on Prostate Growth Inhibitory Efficacy by Decreasing Insulin Growth Factor-1 in Indonesian Human Prostate Cancer Cells

INTRODUCTION: Lycopene has been discussed as a potential effector in the prevention and therapy of prostate cancer. It is red, lipophilic and naturally occurring in many fruits and vegetables, such as tomatoes. Several growth factors, including insulin-like growth factor 1 (IGF-1), play important roles in carcinogenesis and metastasis. IGF-1 is a mitogen that plays important roles in the regulation of proliferation, differentiation, and apoptosis. Binding of IGF-1 to its cognate membrane receptor activates Ras/Raf/MAP kinase signaling pathways, which regulate cell-cycle progression, cell survival, and transformation. Lycopene has its protective effect, which affects multiple IGF-1-activated signaling pathways. Lycopene stimulates apoptosis through intrinsic pathways, by stimulating the pro-apoptotic factor of the mitochondrial cavity such as the Bax/Bak protein (an apoptotic promotor). Although tomatoes are widely consumed in Indonesia, there is no research study about the effect of lycopene on prostate cancer in Indonesia. Hence, this study is conducted to measure the influence of lycopene on the level of IGF-1 in Indonesian human prostate cancer cells. MATERIALS AND METHODS: Prostate cancer cells were studied. In this experimental study, cells were taken from patients with Gleason score 6 and divided into 5 groups: 2 control groups and 3 treatment groups, which were given 1 µM, 2 µM and 4 µM of lycopene, respectively. Measurement of mean IGF-1 level was performed by ELISA. A comparative analysis was performed by two-way ANOVA. RESULTS: The result showed that there was a significant difference in mean IGF-1 levels in the provision of various concentrations of lycopene and time of observation (p<0.05). Increased level of mean IGF-1 appeared on 2µM dose of lycopene at 48 hours observation and began to decline in 72 hours observation. This happened also on 4µM lycopene at 24 hours observation and began to decline in 48 hours observation (p<0.05). CONCLUSION: Lycopene could be administered as adjuvant therapy for prostate cancer patients to increase apoptosis, and eventually inhibit the progressivity of cancer cells.